The nose knows.

Police dogs are trained to sniff out a variety of things, but you may not realize that your phone is one of them.

Electronic storage detection dogs are trained to sniff out devices like hard drives, thumb drives, smartphones and computers. The training program was developed by Connecticut State Police, and they trained their first ESD dog in 2012.

So how do these dogs do it? All electronic devices that have memory storage have a coating of a chemical called triphenylphosphine oxide, or TPPO. This is what the dogs are sniffing out.

"We're fortunate that these devices can't be made without it," said Kerry Halligan of the Connecticut State Police.

Many electronic devices like hard drives and smartphones hold crucial evidence, and criminals often try to hide or bury them. But no matter how cleverly a piece of tech is hidden, it's no match for a powerful canine snout.